Examples for 8th grade - page 83

  1. Friends
    Auticka James and Jaroslav are friends. Together they had 48 toy cars. But if John took 8 cars from Jaroslav, Jaroslav will be have 1.5 times more toy cars than James. How many toy cars had Jaroslav and James?
  2. Metal pyramid
    jehlan_5 Find the weight of a regular quadrilateral pyramid with a 5 cm length and 6,5 cm body height is made from material with density g/cm3.
  3. Midpoints
    rovnobeznik_4 Triangle ABC with sides a = 5 cm, b = 3 cm, c = 40mm has a midpoint of K, L, M. How many centimeters is long perimeter of parallelogram KBLM?
  4. Gardens
    pozemky_1 I have a garden in the shape of a square with a side length of 0.02 kilometers. Neighbor has a large garden as well and one side of the garden we share. I'd bought from a neighbor garden that my area of my garden increased to 5 ares. a/ By how many acres I
  5. Runner 2
    runner2 Marian run 12 meters in 8 seconds. How far would Marian run for 70 seconds, if still run at the same pace?
  6. Kite
    drake_1 John a kite, which is diamond shaped. Its diagonals are 60 cm long and 90 cm long. Calculate: a) the diamond side b) how much paper John needs to make a kite if he needs paper on both sides and needs 5% of the paper for bending.
  7. Tree shadow 3
    tree3_1 A 2-meter rod casts a shadow 3.2 m long. How high is a tree with a shadow of 14.4 m ?
  8. Four integers
    tiles2 Fnd four consecutive integers so that the product of the first two is 70 times smaller than the product of the next two.
  9. Diagonals of a rhombus
    rhombus-diagonals_1 One of the diagonals of a rhombus is twice as the other. If the sum of the lengths of the diagonals is 24, find the area of the rhombus.
  10. Truck and car
    smetiari At 6h45min the truck started at a speed of 36 km/h. At 7h30m behind it a passenger car. Find the average speed of passenger car if it will catch truck 72 km away from the factory.
  11. The swing
    houpacka To swing the two girls. Aneta weight 45 kg and Simon 35 kg weight. How far should sit Simon from the middle of swing so it is balanced, if we know that Aneta is sitting at distance 1,5m? How far are girls sitting apart?
  12. Parallelogram
    kosostvorec_3 Side a of parallelogram is twice longer than side b. Its circumference is 78 dm. Calculate the length of the sides of a parallelogram.
  13. Liters od milk
    milk_cylinder The cylinder-shaped container contains 80 liters of milk. Milk level is 45 cm. How much milk will in the container, if level raise to height 72 cm?
  14. Square
    ctverec_1 Danov's father has a square of 65.25 milligram square of wire with a diagonal. How will the square be big when one mm weighs 7 mg?
  15. EQ2
    eq2_4 Solve quadratic equation: ?
  16. Backpack
    batoh_1 Large backpack cost CZK 1352, little is 35% cheaper. How much we paid for 5 large and 2 small backpacks?
  17. Unknown number 4
    ninth I think number. When I divided its square root by its 1/9, I get a number 1. What number am I thinking?
  18. Circular ring
    mezikruzi Square with area 16 centimeters square are inscribed circle k1 and described circle k2. Calculate the area of circular ring, which circles k1, k2 form.
  19. Equilateral triangle
    rs_triangle_1 The equilateral triangle has a 23 cm long side. Calculate its content area.
  20. Regular quadrilateral pyramid
    pyramid_3 Find the volume and surface of a regular quadrilateral pyramid if the bottom edge is 45 cm long and the pyramid height is 7 cm.

Do you have interesting mathematical example that you can't solve it? Enter it and we can try to solve it.

To this e-mail address we will reply solution; solved examples are also published here. Please enter e-mail correctly and check whether you don't have a full mailbox.